Heat exchanger formed of channel members



Aug. 27, 1957 D. G. PETERSON 2,804,285

HEAT EXCHANGER FORMED CHANNEL MEMBERS Filed Sept. 10, 1952' IN VEN TOR. D4 W0. 6. P1575 5 ON A TTORNE Y United States Patent HEAT EXCHANGER FORMED OF CHANNEL MEMBERS David G. Peterson, Wellsville, N. Y., assignor to The Air Preheater Corporation, New York, N. Y.

The present invention relates to heat exchange apparatus and particularly to improvements in plate type exchangers utilized for the transmission of heat between two confined fluids.

Specifically the present invention contemplates a particular form of heat exchanger having a multiplicity of long narrow passages which provide flow plates for one fluid that moves in a cross-flow relationship with a second fluid. The structure herein disclosed is especially well adapted for handling gases under low and moderate pressures where a high rate of heat transfer is required.

The invention has among its objects a heat exchanger device of the type described which is simple to manufacture, highly efiicient in operation; structurally strong yet light in weight. A further object of this invention is the production of a device in which the component members of a heat exchanger device are all produced from similarly formed channel members.

These and other objects herein disclosed will become apparent to those skilled in the art and my invention herein disclosed is intended to include any obvious departures from the stated objects.

The invention will best be understood upon consideration of the following detailed description of illustrative embodiments thereof Zwhen read in conjunction with the accompanying drawings in which:

Figure 1 is a perspective view of a portion of a plate type heat exchanger embodying the present invention comprising a series of abutting channels.

Figure 2 is a side view in section of the device of Figure 1 along the line 2-2 in Figure 1.

Figure 3 is an end view of the same.

Figure 4 is a side view in section of a device similar to that of Figure 1 in which the channels disposed on opposite sides of the dividing partition are of unlike dimensions.

Figure 5 is an end'section of the device of Figure 4.

The heat exchanger of the invention essentially consists of a series of abutting channel members bonded together so as to form an integral plate member with leg or fin members on one side which comprise an extended surface therefor. The basic unit of this invention consists of a metallic strip having a high heat conductivity and which is otherwise suitable for processing into a heat exchanger unit. This metallic strip is formed into a narrow U-shaped channel member 20 with plane side legs 21 which are easily joined as by brazing to the plane side legs of identical abutting channel members.

Abutting channel members are bonded together continuously along adjoining legs so as to form a composite plate made up of the base parts 23 of the channels with a plane surface on one side and the series of parallel legs 21 extending as fins from the other side thereof. The plane surfaces of two such composite plates are then bonded together back to back so that the fins or legs on one side of the plane surface are normal to similar fins on the other side of the abutting plane surfaces. The resulting product of such an organization is a composite plate like member having strip fins on both sides, the fins 2,804,285 Patented Aug. 27, 1 9 57 on one side running normal to those on the other side so as to direct fluid flow past opposite sides of said plate in a cross-flow relation.

A plurality of such finned plate members are spaced one from the other so that the legs or fins of one plate member cooperate with the fins of a facing plate member so as to form passageways as at 24 across the entire heat exchanger surface. These plate members are maintained spaced by channel members 22 which also serve as side closures to confine each fluid to the space between cooperating finned plates. Each of said channel members 22 is sized so that its yoke is of a length slightly greater than the combined length of the legs of two opposing fins 21 so as to maintain a slight clearance 26 between facing fin members. When channels 20 are arranged in the above described manner, the separation of one fluid from the other is effected without the use of an additional metallic separating plate. It is therefore apparent that by dispensing with such a metallic sheet between each layer of abutting channels, a substantial saving in weight is achieved.

Figures 3 and 4 show an alternate arrangement in which channels 30 and 36 are of unlike dimensions so as to satisfy different operating conditions.

This heat exchanger may be assembled and bonded together by any one of several common procedures. How ever, the preferred method of manufacturing this type of heat exchanger is by furnace brazing. It is intended that no spot-welding be required to hold the various components in place preparatory to the brazing operation. Briefly, the method of assembly before brazing is as follows: The channels are first placed in a suitable fixture or jig, layer by layer with the closure channel members 22 placed upended between the yoke portions of channels 20 which are at right angles thereto in the manner shown in Figures 1 and 2. A metallic strip 38 of predetermined thickness is placed between the ends of the flanges of channels 20 so as to support the channels during the brazing operation and keep them evenly spaced until they are properly bonded together. Between layers of abutting channel members 20, a coating of brazing alloy or brazing copper is placed so that when the entire assembly is subjected to the high temperature of a brazing furnace, the brazing alloy is reduced to a molten state and is subsequently drawn by capillarity action into the spaces between abutting channel members so as to form, upon solidifying, a permanent bond between all such abutting members.

What I claim is:

1. In a plate type heat exchanger wherein one fluid flows through a passageway defined by the inner surfaces of two spaced wall members and a second fluid flows across the outer surface of each wall member in a crossflow relation thereto, each said wall member comprising; a series of juxtaposed channel members lying in a back-toback relation with and normal to a series of similar chan nel members so that web portions of abutting channel members combine to form a plane wall separating one.

fluid from the other and flanges on juxtaposed channel members combine to form extended surface fins, said fins extending into the fluid stream which flows over the separating wall; and spacing means at the sides of said wall members and in a parallel relation to the adjacent extended surface fins for bridging the space between the two walls so that the fluid passageway may be closed at its side edges.

2.. A structure as defined in claim 1 in which the spacing means at the side of said wall members comprises a channel member whose web abuts the adjacent extended surface fins and is of greater length than the combined length of said fins.

3. A structure as defined in claim 1 in which all of said channel members are of a uniform size and shape.

4. A structure as defined in claim 1 in which composite 2,172,667 Nelson Sept. 12, 1939 wall members whose fins extend in one direction are of 2,539,870 Simpelaar Ian. 30; 1951 uniform size, and all fins normal thereto are of a different 2,573,538 Brown Oct. 30, 1951 size. v V, V 4 2,595,457 Holm et a1 May 6, 1952 I l 1 5 2,645,462 Holm July 14, 1953 References Cited 1n the ii e of thls patent H I FOREIGN PATENTS UNITED, STATES PATENTS 510,206 Great Britain July 28, 1939 1,775,819 Fischer et a1. Sept. 16, 1930 668,349 Great Britain Mar. 12. 1952 

